Malaria kills nearly three million people worldwide every year,
mostly in sub-Saharan Africa. Millions of bed nets have been handed
out, and villages across the continent have been doused with
insecticide. But those measures haven't put a significant dent in
malaria cases.

After a string of failed initiatives, the United Nations
recently announced a campaign to provide bed nets to anyone who
needs them by 2010.

Some scientists think creating mutant mosquitoes resistant to
the disease might work better.

"We still have a malaria burden that is increasing," said Yeya
Toure, a tropical disease expert at the World Health Organization.

"Under such circumstances, we have to investigate whether
genetically modified mosquitoes could make a difference," said
Toure, who is not involved in the Imperial College research.

The Bill & Melinda Gates Foundation has found the work so
promising it has invested nearly $38 million into genetic
strategies to stop mosquitoes from transmitting diseases like
malaria and dengue fever.

"This is one of those high-tech, high risk innovations that
would fundamentally change the struggle between humans and
mosquitoes," said Dr. Regina Rabinovich, director of infectious
diseases development at the Gates Foundation.

Mosquitoes bred to be immune to malaria could break the
disease's transmission cycle. "That is the nirvana of malaria
control," said Rabinovich. "It would potentially transform what
the field looks like."

In 2005, Crisanti proved it was possible to create a genetically
modified mosquito by inserting a gene that glowed fluorescent green
in males.

Among other possibilities, he and his team are now planning to
create sterile male mosquitoes to mate with wild female mosquitoes,
thus stunting population growth. They are also trying to engineer a
malaria-resistant mosquito.

Last year, American researchers created mosquitoes resistant to
a type of malaria that infects mice. Others are altering the DNA of
the mosquitoes that spread dengue.

But not everyone thinks these super mosquitoes are such a good
idea. Some scientists think there are too many genetic puzzles to
be solved for modified mosquitoes to work.

The malaria-causing parasite, which mosquitoes then transmit to
humans, is simply too good at evading anything scientists might
devise to protect the mosquito, argued to Jo Lines, a malaria
expert at London's School of Hygiene and Tropical Medicine.

"It's a series of arms races that the parasite has consistently
won," Lines said. Whenever mosquitoes have developed genes
resistant to the malaria-causing parasite, the parasite has always
found a way around it, Lines said.

Quantity might also be a problem. "You are going to need to
produce billions of these mosquitoes if this is ever going to
work," Lines said.